Is light made up of atoms and elements?
- Light is made of photons that have no rest mass and exist as an electromagnetic
ripple in space-time. So No Light is Not Made Out Of elements and atoms.
Explain the relationship between matter, atoms, and elements
- An element is a basic substance that other things are composed from. Each individual element is made up of tiny, invisible particles called atoms.
An atom is the smallest unit of an element that has that element's properties. Both atoms and elements are matter.
Distinguish between elements and compounds
- A compound
contains atoms of different elements
chemically combined together in a fixed ratio. An element
is a pure chemical substance made of same type of atom.Compounds
contain different elements
in a fixed ratio arranged in a defined manner through chemical bonds.
Describe molecules, and explain how they are formed
-
A molecule
is formed
when two or more atoms join together chemically. A compound is a molecule
that contains at least two different elements.
Interpret and write some common chemical formulas
- CO2:
The C indicates that it has one carbon atom.The O2 indicates that it has two oxygen atoms.Note that the subscript, in this case 2, is only for the oxygen atom just before it. It does not affect the carbon atom.
- 2NH3:
For each NH3 molecule, the N indicates that it has one nitrogen atom and the H3indicates that it has three hydrogen atoms.The number 2 in front (called the coefficient) indicates that there are two NH3molecules.So, in total, there are two nitrogen atoms and six hydrogen atoms.
Categorize materials as pure substances or mixtures
- Firstly, a pure substance is matter which cannot be separated into any other kind of matter when using the physical or chemical process. All the particles which make up a pure substance have the same color, taste, composition and texture. In other words, it can be an element or a compound, which consists of only one component with a definite composition, chemical and physical properties.
Secondly, a mixture is a combination of two or more substances which are not united using a chemical procedure. The components that make up a mixture do not exist in fixed proportions, and most of the natural substances that you are familiar with, are mixtures. Examples of mixtures include water, alcohol, oil, and dye.
So what are the distinct differences between these two? With regards to a mixture, it can be physically separated into pure compounds or elements. This is something that is not possible with a pure substance, because it is already a type of matter which exists in its most basic, or purest form.
Another distinct characteristic of a pure substance is that, no matter how physically impossible it may be to isolate a pure substance, it can only be considered as pure if no impurities are detected. When it comes to their physical properties, such as their boiling or melting points, pure substances are non-changing, while mixtures are varying. For example, the boiling point of pure water is at 100 degrees Celsius, while the boiling point of alcohol mixed with water may be at a range of temperatures. To put it simply, pure substances are exactly what the name implies – pure, while mixtures are impure.
